a(n) = sigma_1(k) / phi(k) where k = A020492(n) is the n-th balanced number.

Terms

a(0) =1a(1) =3a(2) =2a(3) =6a(4) =7a(5) =4a(6) =3a(7) =9a(8) =2a(9) =8a(10) =5a(11) =6a(12) =7a(13) =4a(14) =7a(15) =10a(16) =5a(17) =12a(18) =4a(19) =9a(20) =10a(21) =3a(22) =4a(23) =14a(24) =10a(25) =8a(26) =6a(27) =13a(28) =9a(29) =8